Strut Efficiency-Based Design for Concrete Deep Beams Reinforced with Fiber-Reinforced Polymer Bars

Abstract

In this paper, a strut-and-tie-based model is proposed to predict the shear strength of fiber-reinforced polymer-reinforced (FRP) deep beams. An assessment of the available strut-and-tie models (STMs) in ACI and CSA provisions was conducted, identifying the important parameters affecting the strut efficiency factor. The tendency of each parameter (concrete compressive strength, shear span-depth ratio, and strain in longitudinal reinforcement) was assessed against the efficiency factor. The data from the 28 specimens with and without web reinforcement, including 12 tested FRP-reinforced concrete deep beams in our study and 16 FRP-reinforced deep beams taken from the literature, were used to assess the proposed model. The model was capable of capturing the failure mode and predicting the ultimate capacity of the tested FRP-reinforced deep beams. The proposed model was verified against a compilation of databases on 172 steel-reinforced deep beams, resulting in an acceptable level of adequacy.